Texture look lighter in material view than in render view
The material view does not use the lighting in the scene, instead it is lit by the three Solid OpenGL lights that can be set up in the User Preferences: File / User Preferences / System Preferences / Solid OpenGL lights. You can adjust those lights and save the settings, but do not forget, those settings are global, they apply for all blends.

The render view is of cource better than the material view: The former is doing a real render, while the latter approximates it with fast real-time OpenGL rendering.

About tips and tricks for rendering: Those are too broad for Blender Stack Exchange, but you can easily google for Belnder texturing tutorial, and watch some. Blender Guru and Blender Cookie are good sources for tutorials. You can also search for tutorials on BlenderNation.